Messages in this thread | | | Date | Mon, 21 Sep 2015 14:06:36 +0800 | From | Herbert Xu <> | Subject | Re: [PATCH v4] netlink: Fix autobind race condition that leads to zero port ID |
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On Sun, Sep 20, 2015 at 10:55:21PM -0700, David Miller wrote: > From: Herbert Xu <herbert@gondor.apana.org.au> > Date: Fri, 18 Sep 2015 19:16:50 +0800 > > > The commit c0bb07df7d981e4091432754e30c9c720e2c0c78 ("netlink: > > Reset portid after netlink_insert failure") introduced a race > > condition where if two threads try to autobind the same socket > > one of them may end up with a zero port ID. This led to kernel > > deadlocks that were observed by multiple people. > > > > This patch reverts that commit and instead fixes it by introducing > > a separte rhash_portid variable so that the real portid is only set > > after the socket has been successfully hashed. > > > > Fixes: c0bb07df7d98 ("netlink: Reset portid after netlink_insert failure") > > Reported-by: Tejun Heo <tj@kernel.org> > > Reported-by: Linus Torvalds <torvalds@linux-foundation.org> > > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> > > Applied and queued up for -stable, thanks Herbert.
Sorry but Dave but there are still races with v4 as Tejun pointed out. I'm still working on it and I could post them as incremental patches if that's the easiest.
Thanks, -- Email: Herbert Xu <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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